GC Manuals: display bonus exp left on the exp bar

I'm leveling my DoLs in parallel and it's hard to estimate how much of the bonus exp I already consumed, so I usually end up with one of the classes ahead of the other. There are also times I return to the camp not knowing if the manual will last for another leve.

The code is already there, just use the same way to display the bonus exp from the manual as rested exp and add a condition of displaying the additional exp only if you're currently on a class this manual affects.